Commonly, mobile hopper trailers and vehicles are used for carrying bulk commodities such as industrial products such as pelletized plastics and the like, and food products such as milled flours and the like. Typically, the hoppers include multiple sections or compartments for receiving and holding the products, each section or compartment having a generally conical or tapered bottom portion terminating at a discharge outlet. A discharge or dump valve is typically connected to the outlet and to an inverted tee or other fitting located beneath the valve, the tee or other fitting being connected on both ends to generally horizontal pipes or hoses connected in turn to the tees or fittings of the other sections or compartments. In this manner, a generally horizontal path through the fittings connected pipes or hoses is formed for the flow of the materials discharged from the hopper sections or compartments. The discharge or dump valves can selectably be opened to allow the material to be discharged from the selected hopper therethrough, under force of gravity and/or a pressure differential between the hopper section and the flow path, vibration often being used to facilitate the material flow from the hopper and to prevent bridging wherein the material forms a self-supporting arch or dome above the discharge outlet. A pneumatic flow is typically generated through the flow path by a blower or the like disposed at one end of the flow path, to carry the discharged material through the flow path to a receiver or connection at another end of the path.
A disadvantage of many of the known hopper tee and other fitting constructions is that, particularly when used with a valve, they have a substantial downward extent beneath the hopper section, so as to be subject to potential damage from contact with road hazards, particularly railroad tracks and curbs, which the hoppers cross from time to time. And, another disadvantage of the known hopper tees is that if they become damaged, or otherwise are rendered inoperable, for instance, such as due to blockage therein, or the like, they cannot be easily removed from the hopper, without either removing the valve or separately securing the valve to the hopper.
Reference in this regard, Sisk U.S. Pat. No. 5,676,404, issued Oct. 14, 1997, which discloses a low profile flanged tee for a hopper, including in one embodiment thereof an integral flange positioned around an opening formed in a top side of an elongated hollow pipe section, which flange includes an array of holes through which bolts are passed for connection of the tee to the bottom of a hopper, typically with a valve disposed therebetween. Possible shortcomings or disadvantages of the Sisk low profile tee include that, in the event it is required or desired to remove the tee, for instance, due to damage or clogging, the valve must also be removed, or connected in some manner to the hopper separately from the tee. Additionally, when used with a butterfly type valve, the low profile design may result in a lower portion of the valve member being disposed in the horizontal flow path through the tee so as to possibly interfere with material flow therethrough. Further, it is observed that the disclosed embodiments of the Sisk low profile tee do not include bolt holes through the portions of the flange located directly above the horizontal pipe section, which could possibly lead to weakened sealing in those regions.
Thus, what is sought is a hopper fitting, and particularly a tee, having a low vertical profile and other advantages, which overcomes one or more of the shortcomings and disadvantages set forth above.